French designers ModeLabs have come up with three new cell phone concepts that use the inherent motion of their use to charge them up. The first (and most practical/interesting, in my opinion) is the U-Turn, a phone that gets juiced up by flipping the keyboard out. Less practical are the YoYo, getting charged by bouncing around while hanging around your neck, and Runaway, which gets its juice by being attached to your wrist while you run.

That's the U-Turn up above, on the other side check out the YoYo and Runaway. What do you guys think, will this sort of thing catch on? It seems like such limited motion couldn't fully charge a phone, but it would be a nice supplement and could help end the stranded feeling you get when your phone dies when you're out away from a charger.